The continual development and commercialisation of new wireless transmission technologies inevitably results in increasing competition for limited bandwidth resources, since only certain frequencies in the electromagnetic spectrum can be used. Examples of technologies to which spectrum must be allocated included mobile telecommunications networks, wireless networking systems (e.g. WLAN, Bluetooth, Zigbee etc.), global navigation satellite systems (GNSS) such as GPS, Galileo and GLONASS, and conventional terrestrial and satellite broadcasting services.
Because the availability of bandwidth in a broadcasting portion of the spectrum is limited, various methods have been developed in recent years to allow new services to be distributed over the Internet. Examples of known techniques include over-the-top (OTT) techniques such as Dynamic Adaptive Streaming over HTTP (DASH), or managed techniques such as multicast Real-time Transfer Protocol (RTP). For example, in the UK there are currently around 70 services provided using OTT. In addition, systems have been proposed in which the various components making up a service are delivered via a combination of a broadcast stream and the Internet. A receiver can receive data from both sources and merge them to present the service to the user.
However, although such methods allow new broadcast services to be provided without using additional bandwidth in the electromagnetic spectrum, they are not able to reduce the bandwidth usage of existing broadcasting services.
The invention is made in this context.